Would wiring three 5W LED lights to the 6V wire on the BBS01b be too much for the controller?

Because so many drivers have bicycle-blindness, I'd like to wire two of these 6V headlamps to my handlebar:

 

https://www.amazon.co.uk/Junstar-Electric-Headlamp-Waterproof-Headlight/dp/B07DJCT5G7/

 

...and one of these tail lights, to the 6V connector for lights from the controller on the Bafang BBS01b:

 

https://www.amazon.co.uk/Junstar-eBike-light-Bafang-Electric/dp/B07J25CX7V/

 

According to the Amazon listing, each headlight is 5W... so at 6V that's 0.83A. If I assume the tail light is also 5W (there's nothing on the listing about watts), that's 2.49A in total - would this be too much for the controller? How much current can that output cope with? Would doing so, damage the bbs01b controller? Is there an easily replaceable fuse inside? Should I connect the lights in series or parallel? What's the worst that could happen? There are "Compatible" replacement controllers in case I kill the one I have, but none that I've seen have the 6V cable for lights, therefore I'd prefer to not damage it... or attempt one of my highly inept electronics repairs.

Edited September 16, 20214 yr by guerney

Because so many drivers have bicycle-blindness, I'd like to wire two of these 6V headlamps to my handlebar:

 

https://www.amazon.co.uk/Junstar-Electric-Headlamp-Waterproof-Headlight/dp/B07DJCT5G7/

 

...and one of these tail lights, to the 6V connector for lights from the controller on the Bafang BBS01b:

 

https://www.amazon.co.uk/Junstar-eBike-light-Bafang-Electric/dp/B07J25CX7V/

 

According to the Amazon listing, each headlight is 5W... so at 6V that's 0.83A. If I assume the tail light is also 5W (there's nothing on the listing about watts), that's 2.49A in total - would this be too much for the controller? How much current can that output cope with? Would doing so, damage the bbs01b controller? Is there an easily replaceable fuse inside? Should I connect the lights in series or parallel? What's the worst that could happen? There are "Compatible" replacement controllers in case I kill the one I have, but none that I've seen have the 6V cable for lights, therefore I'd prefer to not damage it... or attempt one of my highly inept electronics repairs.

Those lights will work direct from the battery. Wouldn't it be easier and safer and more efficient to wire them in there?

Those lights will work direct from the battery. Wouldn't it be easier and safer and more efficient to wire them in there?

 

One of these between the battery and the motor?

 

https://www.amazon.co.uk/XLX-High-power-Converter-Adjustable-Protection/dp/B081X5YX8V

I have the six volt bafang front light on mine and it is controlled by the handlebar switch and also by the light sensor in the display unit, so it comes on automatically in low light.

 

I wanted to wire in a blinky type rear light, so I took an old one and set it up to connect to wires rather than the battery, and I wired it in parallel with the front light connectors down by the motor. This did not work. The blinky came on, but the front light would not operate.

 

I think the buck convertor connected to the battery directly would be your best bet for more lighting than is provided by the purpose made bafang front light. That bafang front light is quite good by the way. I have used it on dark country roads and it lit up the road fine. I just wish they'd thought about a tail light too.

I have the six volt bafang front light on mine and it is controlled by the handlebar switch and also by the light sensor in the display unit, so it comes on automatically in low light.

 

I wanted to wire in a blinky type rear light, so I took an old one and set it up to connect to wires rather than the battery, and I wired it in parallel with the front light connectors down by the motor. This did not work. The blinky came on, but the front light would not operate.

 

I think the buck convertor connected to the battery directly would be your best bet for more lighting than is provided by the purpose made bafang front light. That bafang front light is quite good by the way. I have used it on dark country roads and it lit up the road fine. I just wish they'd thought about a tail light too.

 

That's good to know. Looks like I'll need a suitable step down transformer which won't make my battery burst into flames at an inopportune time, and some sort of waterproof housing for it, perhaps with a heatsink. There's an attachment for the handlebar for those Bafang lights by the way, I bought one a few weeks ago which allows (a bit of) variation left and right as well as up and down, before you lock it into the right angle, I'll try and find the link. I'll need a second one one of those.

 

I made a blinky out of one of those cheap "Cree" torches which use one AA battery, for the back of the bike - I went over the interior of glass lens with a permanent red marker pen to make it the appropriate colour for a rear light. It's a lot brighter than the average blinky, and lasts about two and a quarter hours on nimh.

Edited September 16, 20214 yr by guerney

That's good to know. Looks like I'll need a suitable step down transformer which won't make my battery burst into flames at an unopportune time, and some sort of waterproof housing for it, perhaps with a heatsink. There's an attachment for the handlebar for those Bafang lights by the way, I bought one a few weeks ago which allows (a bit of) variation left and right as well as up and down, before you lock it into the right angle, I'll try and find the link. I'll need a second one one of those.

 

I made a blinky out of one of those cheap "Cree" torches which use one AA battery, for the back of the bike - I went over the interior of glass lens with a permanent red marker pen to make it the appropriate colour for a rear light. It's a lot brighter than the average blinky, and lasts about two and a quarter hours on nimh.

Transformers are designed for AC, generally speaking.

E-bikes are DC.

You need a DC to DC converter if no provision has otherwise been made on your bike for low voltage lighting.

Many lights for e-bikes are designed & made to accept higher voltages, as someone has already mentioned here....

regards

Andy

Transformers are designed for AC, generally speaking.

E-bikes are DC.

You need a DC to DC converter if no provision has otherwise been made on your bike for low voltage lighting.

Many lights for e-bikes are designed & made to accept higher voltages, as someone has already mentioned here....

regards

Andy

 

Are you saying that I can wire these lights in parallel directly between the motor and battery, without using a buck converter to step the voltage down to 6V?

Are you saying that I can wire these lights in parallel directly between the motor and battery, without using a buck converter to step the voltage down to 6V?

Before you try that - DO check the voltage rating on your lamps. AndyMatt said 'many lights'. He did not say all ebike lights can accept higher voltages.

Before you try that - DO check the voltage rating on your lamps. AndyMatt said 'many lights'. He did not say all ebike lights can accept higher voltages.

 

They're advertised as 6V lights, can't harm the battery trying? I'll connect one to see if it dies, when they arrive in the post in about a week.

If there's a short circuit in the lights due to poor waterproofing, when it's connected directly to the battery, that would be a brown trouser situation - it'll have to be a buck converter fix for these three 6V lights.

Are you saying that I can wire these lights in parallel directly between the motor and battery, without using a buck converter to step the voltage down to 6V?

It depends upon the design of the lights. Some of them already have some form of DC to DC converter built in. Which is often on cheaper lights, is simply a "dropper" resistor with a reasonable wattage to handle the LED light current.

These do "waste" a tiny bit of current (your bike battery at night may run one mile less per 20 miles of travel for example), in raising the temperature of the resistor when the light is switched on, (some people see this as a BIG disadvantage!! DUUHHH!) but in comparison to using more complicated electronics which are obviously far less robust than a simple resistor when it rains for example, but "save" a tiny bit of current, at a higher cost to the end user.....and are far more likely to fail.....a correctly sized dropper resistor for such lights will only cost a few pence to replace....if it ever fails!

"You Pays Your Money and Makes Your Choice" :- as we used to say in bad English!

By the way, to calculate the size and wattage of the dropper resistor for a bike light without any form of DC to DC conversion, you just need to know the value of current drawn in use and the voltage the light was designed to use. For such usages, I generally would purchase a quality ceramic resistor of the correct value Ohms wise, with a wattage rating of at least twice the planned wattage, as it will run much cooler.

A heat sink may be a good idea, say one attaching to the lights interior metal case for example....There are many useful options in that area....too many to list in a post!

If you have any further questions, simply post your question.

Have a great day.

regards

Andy

Are you saying that I can wire these lights in parallel directly between the motor and battery, without using a buck converter to step the voltage down to 6V?

I believe I answered that above for you.

But unless you KNOW that some form of DC to DC converter is reducing the voltage to that required by the bike light, my answer is NOT TO TRY IT! In a bad case scenario, you might even start a small fire in your wiring!

Also, I forgot to mention, a suitably sized fuse in circuit (one for each light) is always a good idea.....inline fuses are safe, easy and cheap.

regards

Andy

I believe I answered that above for you.

But unless you KNOW that some form of DC to DC converter is reducing the voltage to that required by the bike light, my answer is NOT TO TRY IT! In a bad case scenario, you might even start a small fire in your wiring!

Also, I forgot to mention, a suitably sized fuse in circuit (one for each light) is always a good idea.....inline fuses are safe, easy and cheap.

regards

Andy

 

So before I try wiring in these lights directly to the battery, I should open one up to see if it contains a DC to DC converter. They're only £10 each, I don't mind destroying one if necessary to find out.

 

What size fuse do you recommend? Also, is there a well made waterproof housing that would be suitable for the inline fuses?

So before I try wiring in these lights directly to the battery, I should open one up to see if it contains a DC to DC converter. They're only £10 each, I don't mind destroying one if necessary to find out.

 

What size fuse do you recommend? Also, is there a well made waterproof housing that would be suitable for the inline fuses?

This depends on the wattage/Current draw of the light.

Just for example:-

if it draws 1 amp at the correct voltage, then a 2 amp "Quick blo" or "Normal-Blo" fuse would be about right for normal usage.

This is just an example, I have no idea how much current your light draws.......But a fuse of double the normal running current, would give a reasonably safe usage.

Do not use so called "Slo-Blo" fuses, as they take too long to break, and may subject your bike's wiring to too much heat stress....or other parts of the bike's electronics......also never use a fuse, even in an emergency, of a higher rating - as you WILL regret that!! Silver foil is a good, sorry BAD, example of that.....never, ever use it!!

Take spare fuses with you on a ride, ones of the correct type of course....and any tools that may be required.

regards

Andy

This depends on the wattage/Current draw of the light.

Just for example:-

if it draws 1 amp at the correct voltage, then a 2 amp "Quick blo" or "Normal-Blo" fuse would be about right for normal usage.

This is just an example, I have no idea how much current your light draws.......But a fuse of double the normal running current, would give a reasonably safe usage.

Do not use so called "Slo-Blo" fuses, as they take too long to break, and may subject your bike's wiring to too much heat stress....or other parts of the bike's electronics......also never use a fuse, even in an emergency, of a higher rating - as you WILL regret that!! Silver foil is a good, sorry BAD, example of that.....never, ever use it!!

Take spare fuses with you on a ride, ones of the correct type of course....and any tools that may be required.

regards

Andy

I forgot to mention, if the details that came with the lights speaks of 6 volts, then plan for that voltage.

It is IMHO highly unlikely that lights for 6 volts will be fitted with any form of DC to DC converter.....or the documentation would have mentioned it!

regards

Andy

I forgot to mention, if the details that came with the lights speaks of 6 volts, then plan for that voltage.

It is IMHO highly unlikely that lights for 6 volts will be fitted with any form of DC to DC converter.....or the documentation would have mentioned it!

regards

Andy

 

Thanks Andy, I'll do some reading and research.

Thanks Andy, I'll do some reading and research.

Come back to us (all!), if any further clarification is needed, as an explanation will be cheaper than an error!

Andy

Because so many drivers have bicycle-blindness, I'd like to wire two of these 6V headlamps to my handlebar:

 

https://www.amazon.co.uk/Junstar-Electric-Headlamp-Waterproof-Headlight/dp/B07DJCT5G7/

 

...and one of these tail lights, to the 6V connector for lights from the controller on the Bafang BBS01b:

 

https://www.amazon.co.uk/Junstar-eBike-light-Bafang-Electric/dp/B07J25CX7V/

 

According to the Amazon listing, each headlight is 5W... so at 6V that's 0.83A. If I assume the tail light is also 5W (there's nothing on the listing about watts), that's 2.49A in total - would this be too much for the controller? How much current can that output cope with? Would doing so, damage the bbs01b controller? Is there an easily replaceable fuse inside? Should I connect the lights in series or parallel? What's the worst that could happen? There are "Compatible" replacement controllers in case I kill the one I have, but none that I've seen have the 6V cable for lights, therefore I'd prefer to not damage it... or attempt one of my highly inept electronics repairs.

 

I looked at doing this on one of our ebikes. In the end went for some Moon USB rechargeable front and back lights.

 

These are far brighter that the factory fitted front light and there is no potential risk of damage to the ebike or warranty.

One of these between the battery and the motor?

 

https://www.amazon.co.uk/XLX-High-power-Converter-Adjustable-Protection/dp/B081X5YX8V

You don't need anything - just wires. The lights already can run off any voltage up to 80v. It's not very efficient to run them off the 6v supply because there are too many conversion losses. Running from the battery, there is only one conversion, and that's inside the light.

I forgot to mention, if the details that came with the lights speaks of 6 volts, then plan for that voltage.

They're not 6v lights. They're LEDs with a driver that runs from 6v to 80v. I thought you said you knew about electronics.

 

Why do you keep encouraging people to burn their money and their stuff? Are you some sort of sadist. Stay out when you don't know what you're talking about. If he connects those 4 lights, he'll most likely be looking for a new controller, which is more than £60.

Edited September 16, 20214 yr by vfr400

You don't need anything - just wires. The lights already can run off any voltage up to 80v. It's not very efficient to run them off the 6v supply because there are too many conversion losses. Running from the battery, there is only one conversion, and that's inside the light.

 

Thank you, that's good to know - I'll add inline fuses, they seem like a good idea before I connect anything up.

Below are the light's spec ,they have an integral buck converter. As vfr says wire direct off the battery/controller supply and run them off a switch and if you like an inline fuse.

 

985CS Features:

 

1. Power: 3 W

 

2. Input:DC 6 V-80 V

 

3. Brightness:5050 3 V LED >60 lux

 

4. Standard:Europe DC-6 V/9 W System

 

5. Material:Aluminum,high quality e-bike light

 

6. Wire:Length 1.5 meter

 

7. IP X 3 waterproof,heavy rain waterproof

 

8. Temperature:<48

 

 

 

EF-707CS Features:

 

1. Power:5 W

 

2. Input: DC 6 V-80 V

 

3. Brightness:5050 3 V LED >100 lux

 

4. Material:Aluminum,high quality e-bike light

 

5. Wire:Length 1.5 meter

Below are the light's spec ,they have an integral buck converter. As vfr says wire direct off the battery/controller supply and run them off a switch and if you like an inline fuse.

 

985CS Features:

 

1. Power: 3 W

 

2. Input:DC 6 V-80 V

 

3. Brightness:5050 3 V LED >60 lux

 

4. Standard:Europe DC-6 V/9 W System

 

5. Material:Aluminum,high quality e-bike light

 

6. Wire:Length 1.5 meter

 

7. IP X 3 waterproof,heavy rain waterproof

 

8. Temperature:<48

 

 

 

EF-707CS Features:

 

1. Power:5 W

 

2. Input: DC 6 V-80 V

 

3. Brightness:5050 3 V LED >100 lux

 

4. Material:Aluminum,high quality e-bike light

 

5. Wire:Length 1.5 meter

 

Thank you for taking the trouble to look those details up. I've just found this, which might be worth buying - it goes between the controller and the battery, lights are switched on via the display and it also provides brake light functionality:

 

https://www.ebay.co.uk/itm/403054641641

...and here's an explanatory diagram of the connectors on that group adapter cable:

 

https://www.picclickimg.com/d/l400/pict/124708846691_/6V-Adapter-Cable-Bafang-Drive-Group-Lamp-Retrofit.jpg

There's a 3A limit on that group adapter, but at 36V and 5W per light = 0.13888888889A per light, would that mean I could have 21.5999 lights connected? Not that I would, of course ... I wonder if that's a buck converter down to 6V, on the cable?